Translate ch06-03 in french.

FRENCH/examples-sources/06_03_select/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "example_06_03_select"
+version = "0.1.0"
+authors = ["Taylor Cramer <cramertj@google.com>"]
+edition = "2018"
+
+[lib]
+
+[dev-dependencies]
+futures = "0.3"

FRENCH/examples-sources/06_03_select/src/lib.rs

@@ -0,0 +1,183 @@
+#![cfg(test)]
+#![recursion_limit="128"]
+
+mod example {
+// ANCHOR: example
+use futures::{
+    future::FutureExt, // for `.fuse()`
+    pin_mut,
+    select,
+};
+
+async fn task_one() { /* ... */ }
+async fn task_two() { /* ... */ }
+
+async fn race_tasks() {
+    let t1 = task_one().fuse();
+    let t2 = task_two().fuse();
+
+    pin_mut!(t1, t2);
+
+    select! {
+        () = t1 => println!("task one completed first"),
+        () = t2 => println!("task two completed first"),
+    }
+}
+// ANCHOR_END: example
+}
+
+mod default_and_complete {
+// ANCHOR: default_and_complete
+use futures::{future, select};
+
+async fn count() {
+    let mut a_fut = future::ready(4);
+    let mut b_fut = future::ready(6);
+    let mut total = 0;
+
+    loop {
+        select! {
+            a = a_fut => total += a,
+            b = b_fut => total += b,
+            complete => break,
+            default => unreachable!(), // never runs (futures are ready, then complete)
+        };
+    }
+    assert_eq!(total, 10);
+}
+// ANCHOR_END: default_and_complete
+
+#[test]
+fn run_count() {
+    futures::executor::block_on(count());
+}
+}
+
+mod fused_stream {
+// ANCHOR: fused_stream
+use futures::{
+    stream::{Stream, StreamExt, FusedStream},
+    select,
+};
+
+async fn add_two_streams(
+    mut s1: impl Stream<Item = u8> + FusedStream + Unpin,
+    mut s2: impl Stream<Item = u8> + FusedStream + Unpin,
+) -> u8 {
+    let mut total = 0;
+
+    loop {
+        let item = select! {
+            x = s1.next() => x,
+            x = s2.next() => x,
+            complete => break,
+        };
+        if let Some(next_num) = item {
+            total += next_num;
+        }
+    }
+
+    total
+}
+// ANCHOR_END: fused_stream
+}
+
+mod fuse_terminated {
+// ANCHOR: fuse_terminated
+use futures::{
+    future::{Fuse, FusedFuture, FutureExt},
+    stream::{FusedStream, Stream, StreamExt},
+    pin_mut,
+    select,
+};
+
+async fn get_new_num() -> u8 { /* ... */ 5 }
+
+async fn run_on_new_num(_: u8) { /* ... */ }
+
+async fn run_loop(
+    mut interval_timer: impl Stream<Item = ()> + FusedStream + Unpin,
+    starting_num: u8,
+) {
+    let run_on_new_num_fut = run_on_new_num(starting_num).fuse();
+    let get_new_num_fut = Fuse::terminated();
+    pin_mut!(run_on_new_num_fut, get_new_num_fut);
+    loop {
+        select! {
+            () = interval_timer.select_next_some() => {
+                // The timer has elapsed. Start a new `get_new_num_fut`
+                // if one was not already running.
+                if get_new_num_fut.is_terminated() {
+                    get_new_num_fut.set(get_new_num().fuse());
+                }
+            },
+            new_num = get_new_num_fut => {
+                // A new number has arrived -- start a new `run_on_new_num_fut`,
+                // dropping the old one.
+                run_on_new_num_fut.set(run_on_new_num(new_num).fuse());
+            },
+            // Run the `run_on_new_num_fut`
+            () = run_on_new_num_fut => {},
+            // panic if everything completed, since the `interval_timer` should
+            // keep yielding values indefinitely.
+            complete => panic!("`interval_timer` completed unexpectedly"),
+        }
+    }
+}
+// ANCHOR_END: fuse_terminated
+}
+
+mod futures_unordered {
+// ANCHOR: futures_unordered
+use futures::{
+    future::{Fuse, FusedFuture, FutureExt},
+    stream::{FusedStream, FuturesUnordered, Stream, StreamExt},
+    pin_mut,
+    select,
+};
+
+async fn get_new_num() -> u8 { /* ... */ 5 }
+
+async fn run_on_new_num(_: u8) -> u8 { /* ... */ 5 }
+
+// Runs `run_on_new_num` with the latest number
+// retrieved from `get_new_num`.
+//
+// `get_new_num` is re-run every time a timer elapses,
+// immediately cancelling the currently running
+// `run_on_new_num` and replacing it with the newly
+// returned value.
+async fn run_loop(
+    mut interval_timer: impl Stream<Item = ()> + FusedStream + Unpin,
+    starting_num: u8,
+) {
+    let mut run_on_new_num_futs = FuturesUnordered::new();
+    run_on_new_num_futs.push(run_on_new_num(starting_num));
+    let get_new_num_fut = Fuse::terminated();
+    pin_mut!(get_new_num_fut);
+    loop {
+        select! {
+            () = interval_timer.select_next_some() => {
+                // The timer has elapsed. Start a new `get_new_num_fut`
+                // if one was not already running.
+                if get_new_num_fut.is_terminated() {
+                    get_new_num_fut.set(get_new_num().fuse());
+                }
+            },
+            new_num = get_new_num_fut => {
+                // A new number has arrived -- start a new `run_on_new_num_fut`.
+                run_on_new_num_futs.push(run_on_new_num(new_num));
+            },
+            // Run the `run_on_new_num_futs` and check if any have completed
+            res = run_on_new_num_futs.select_next_some() => {
+                println!("run_on_new_num_fut returned {:?}", res);
+            },
+            // panic if everything completed, since the `interval_timer` should
+            // keep yielding values indefinitely.
+            complete => panic!("`interval_timer` completed unexpectedly"),
+        }
+    }
+}
+
+// ANCHOR_END: futures_unordered
+}

FRENCH/examples-sources/Cargo.toml

@@ -1,3 +1,4 @@
 [workspace]
 members = [
+  "06_03_select",
 ]

FRENCH/examples/06_03_select/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "example_06_03_select"
+version = "0.1.0"
+authors = ["Taylor Cramer <cramertj@google.com>"]
+edition = "2018"
+
+[lib]
+
+[dev-dependencies]
+futures = "0.3"